Isolation and Characterization of 89K Pathogenicity Island-Positive ST-7 Strains ofStreptococcus suisSerotype 2 from Healthy Pigs, Northeast China

Abstract

Streptococcus suisis a swine pathogen which can also cause severe infection, such as meningitis, and streptococcal-like toxic shock syndrome (STSS), in humans. In China, most of theS. suisinfections in humans were reported in the southern areas with warm and humid climates, but little attention had been paid to the northern areas. Data presented here showed that the virulent serotypes 1, 2, 7, and 9 ofS. suiscould be steadily isolated from the healthy pigs in the pig farms in all the three provinces of Northeast China. Notably, a majority of the serotype 2 isolates belonged to the 89K pathogenicity island-positive ST-7 clone that had historically caused the human STSS outbreaks in the Sichuan and Jiangsu provinces of China, although the human STSS case caused byS. suishad never been reported in northern areas of China. Data presented here indicated that the survey ofS. suisshould be expanded to or reinforced in the northern areas of China.